This application claims the priority of German Patent Document DE 101 35 931.4, filed on Jul. 24, 2001, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a motorcycle frame with two longitudinal support tubes, the one end of which is connected, in any given case, with a steering head bearing tube, whereby at least one frame element forms a motor oil reservoir.
A triangular motorcycle frame is known from DE 690 067 69 T2 with a steering head bearing tube in which the handlebar is pivoted and with which an upper main tube and a lower main tube are connected centrally or in the middle. The upper main tube and the lower main tube are connected with each other by a bridging tube running obliquely downward. Such a motorcycle frame where the frame tubes lie in the central longitudinal plane of the motorcycle is designated as a “central frame.” The upper main tube, the lower main tube and the bridging tube form a closed fluid system, which is used as a motor oil reservoir and to which a motor oil inflow and a motor oil outflow are connected.
For motorcycle motors with dry sump lubrication an oil reservoir is needed which is either contained in the frame construction as additional volume, as explained above, or which is formed by a separate oil container. With the high performance data of modern motorcycle motors, a chassis which is as stable as possible and distortion-resistant is required. Central frames are only suited for this conditionally since they have a relatively low torsion stability.
An aspect of the invention is to create a motorcycle frame with integrated motor oil reservoir and an improved stability.
This aspect is accomplished in that the motorcycle frame is a bridge frame, the longitudinal support tubes which are arranged basically symmetrically in relation to a central longitudinal plane of the motorcycle frame, and which are connected with each other in the region between the steering head bearing tube and its other end by a front cross tube near the steering head bearing and by a rear cross tube, whereby the longitudinal support tubes and the cross tubes have a fluid connection with each other and form the motor oil reservoir. Advantageous configurations and refinements of the invention are to be inferred from the preferred embodiments.
A basic principle of certain preferred embodiments of the invention is embodied in the use of a “bridge frame” into which the motor oil reservoir is incorporated. A bridge frame has two longitudinal tubes arranged at a distance from each other and basically symmetrical to the central long plane of the motorcycle, the one end of which is connected with the steering head bearing tube, respectively and which, in the region between the steering head bearing tube and its other end, are connected with each other by a front cross tube near the steering head bearing and a rear cross tube. In accordance with certain preferred embodiments of the invention, the longitudinal support tubes and the cross tubes form a closed fluid system, which is used as a motor oil reservoir.
The bridge frame runs obliquely backward from the steering head bearing tube in the direction of the center of the motorcycle toward the transmission. In the region between the two longitudinal support tubes and the cross tubes, the motor and the radiator of the motorcycle are arranged. With a bridge frame, the motor serves as a “carrying element.” Bridge frame constructions are designed such that they have the greatest stability possible and a light weight, whereby the frame cross-sections are large and the wall thicknesses of the frames are small. The closed frame profile of a bridge frame consequently encloses a relatively large hollow volume, which is used as a motor oil reservoir or as an oil tank.
According to a refinement of an embodiment of the invention, a filler neck is provided on one of the two longitudinal support tubes or lateral profiles for oil filling in the region of the steering head bearing. The filler neck is basically arranged vertically and encloses a concave angle with the longitudinal support tube that is shaped obliquely backward. A seal with an oil measuring stick fastened thereupon is arranged on the opening of the filler neck, which is flexible so that it can fit, when inserted, into the filler neck of the allocated longitudinal support tube corresponding to the interior space contour of the motor oil reservoir of the longitudinal support tube. Consequently, filling with oil and checking the oil are possible through a single “opening.”
The motor oil reservoir of the bridge frame is attached to the motor oil circulation through a motor oil inflow leading to the motor and a motor oil reflux coming from the motor. The inflow to the motor is arranged on the rear or lower cross tube of the bridge frame. An oil filter or an oil strainer is provided between an inflow connection arranged on the upper cross tube and the motor which filters out residues or impurities from the oil and prevents these from getting into the motor oil circulation. A reflux connection is arranged on the upper cross tube, which enables a return of the motor oil into the two frame profiles or longitudinal support tubes. Owing to the relatively large frame surface in comparison to a central frame, an improved heat removal is guaranteed in addition.
According to a refinement of certain preferred embodiments of the invention, so-called surge protection elements are arranged in the longitudinal support tubes of the bridge frame. The surge protection elements have the function of a stop valve. They are supposed to enable a motor oil flow from the upper or forward cross tube to the lower or rear cross tube and prevent a reversed motor oil flow, for example, with a hard braking of the motorcycle, in order to ensure a dependable provision of the motor by holding back motor oil even with strong vehicular delays.
The surge protection elements are preferably made of plastic and are pressed into the longitudinal support tubes before the individual frame tubes are connected with one another, for example by pressure welding.
The surge protection elements have at all times a frame or mounting element, which has in the undeflected state a certain excess in relation to the internal dimensions of the longitudinal tubes and consequently seals in the pressed-in state. A flap-like element is arranged on the frame or mounting element which functions as a “stop flap” and is swivellable in the direction of the rear cross tube. The flap-like element can, for example, be a “plastic flap” fastened unilaterally on the frame of the surge protection element. Through the surge protection element, a secure oil provision for the motor is therewith guaranteed even with heavy braking, especially with full braking.
According to an embodiment of the invention, heat and contact protection elements are arranged on exteriors of the longitudinal support tubes facing away from one another. These “shields” are provided for shielding the legs of the driver and prevent an excessively heat action upon the driver.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.